Study links urge to pee with impairment

Peter Snyder, professor of neurology, found that the need to urinate impairs cognitive function.

“They made it to the bathroom, but it was a pretty ugly scene,” said Peter Snyder, professor of neurology. “There was a bit of some pushing to get into the stalls.”

Snyder was not describing a frat house on a Saturday night or the mad dash for the ladies’ room during the intermission of a lengthy play. Instead, he was talking about his study, which took one afternoon, cost less than $2 and ultimately won him and his team a 2012 MSNBC Weird Science award. The study also caught the eye of the team of Nobel Laureates who determined the winners of the 2011 Ig Nobel Prizes, designed to “honor achievements that first make people laugh, and then make them think,” according to their website.

Snyder’s research showed that the painful need to urinate causes levels of cognitive deterioration on par with staying awake for 24 consecutive hours or having a blood alcohol content level of 0.05, just shy of the legal limit for driving.

But Snyder did not set out to determine the effects of a full bladder. In order to test the effects of drugs on people’s mental capabilities, Snyder’s team was trying to design cognitive tests that would resist the “practice effect” — the improvement that subjects show after being tested multiple times in the same day.

But a test that avoids the practice effect still must be able to measure small changes in cognitive performance.

Using pain to affect cognition is an old idea, Snyder said, but his team was the first to ask people to withhold their urine. Snyder and his colleague, Paul Maruff, came up with this idea after realizing that “the urge to void” is not only painful but is also easily relieved and cheap, Snyder said. The entire study cost around $1.25, far less than the thousands of dollars his usual brain-imaging research requires.

Snyder and his team ran the study on eight individuals, who each drank 250 milliliters of water every 15 minutes until they reached their “breaking point,” where they could no longer hold their urine. As subjects’ self-reported pain levels increased, so too did their levels of cognitive impairment as measured by simple tasks on the computer that tested attention and working memory.

Snyder said the results reflect the anatomical organization of the underlying neural networks that are involved in modulating pain and sustaining concentration — two networks he said are close together.

GeertCrombez, a professor of health psychology at Ghent University in Belgium who researches how pain affects cognition, described Snyder’s study as “weird, but fascinating” in an email to The Herald.

“It is in line with our theoretical model, which essentially states that there are some basic motives that demand urgent action,” he wrote. “These urges interrupt and call for additional attentional resources. They also need to be controlled at the expense of cognitive resources.”

The study’s results have real-world implications Snyder and his team did not anticipate. “We didn’t set out to really talk about the risk of driving when you really need to break to go to the bathroom,” he said. “Honestly, this didn’t occur to us, that it’s the same as drinking until you are too drunk to drive.”

Since publishing the study, he said he has heard from truck drivers who have experienced first-hand cognitive impairment from needing to pee. “At least three or four people who are either truck drivers themselves or are related to truck drivers have told me that they almost killed themselves because they weren’t paying attention when they had to go so badly,” he said.

Since winning the Ig Nobel Prize last year, Snyder has added a “Dubious Honors” section to his resume. “If you can’t laugh at what you do sometimes, then there’s a problem,” he said.

This is so true! I got a traffic ticket (going over speed the speed limit of 45 by 15 miles) when I inadvertently started accelerating my car to get to the next closest bath room (a fast food place about 1/2 mile away) when I started that very uneasy feeling in my bladder to pee. I was diagnosed with urinary incontinence and taking medication but that did not help much on that day.